<!DOCTYPE html>

































































<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link rel="shortcut icon" type="image/x-icon" href="../../../favicon.ico" />
<title>Security and Permissions | Android Developers</title>
<link href="../../../assets/android-developer-docs-devguide.css" rel="stylesheet" type="text/css" />
<script src="../../../assets/search_autocomplete.js" type="text/javascript"></script>
<script src="../../../assets/jquery-resizable.min.js" type="text/javascript"></script>
<script src="../../../assets/android-developer-docs.js" type="text/javascript"></script>
<script src="../../../assets/prettify.js" type="text/javascript"></script>
<script type="text/javascript">
  setToRoot("../../../");
</script>
<noscript>
  <style type="text/css">
    html,body{overflow:auto;}
    #body-content{position:relative; top:0;}
    #doc-content{overflow:visible;border-left:3px solid #666;}
    #side-nav{padding:0;}
    #side-nav .toggle-list ul {display:block;}
    #resize-packages-nav{border-bottom:3px solid #666;}
  </style>
</noscript>
</head>
<body class="gc-documentation">

  <div id="header">
      <div id="headerLeft">
          <a href="../../../index.html" tabindex="-1"><img
              src="../../../assets/images/bg_logo.png" alt="Android Developers" /></a>
          <ul id="header-tabs" class="guide">
    
	<li id="home-link"><a href="../../../offline.html">
	
		<span class="en">Home</span>
		<span style="display:none" class="de">Startseite</span>
		<span style="display:none" class="es"></span>
		<span style="display:none" class="fr"></span>
		<span style="display:none" class="it"></span>
		<span style="display:none" class="ja">ホーム</span>
		<span style="display:none" class="zh-CN">主页</span>
		<span style="display:none" class="zh-TW">首頁</span>
	
	</a></li>
	<li id="sdk-link"><a href="../../../sdk/index.html">
		<span class="en">SDK</span>
	</a></li>
	<li id="guide-link"><a href="../../../guide/index.html" onClick="return loadLast('guide')">
	
		<span class="en">Dev Guide</span>
		<span style="display:none" class="de">Handbuch</span>
		<span style="display:none" class="es">Guía</span>
		<span style="display:none" class="fr">Guide</span>
		<span style="display:none" class="it">Guida</span>
		<span style="display:none" class="ja">開発ガイド</span>
		<span style="display:none" class="zh-CN">开发人员指南</span>
		<span style="display:none" class="zh-TW">開發指南</span>
	
	</a></li>
	<li id="reference-link"><a href="../../../reference/packages.html" onClick="return loadLast('reference')">
	
		<span class="en">Reference</span>
		<span style="display:none" class="de">Referenz</span>
		<span style="display:none" class="es">Referencia</span>
		<span style="display:none" class="fr">Référence</span>
		<span style="display:none" class="it">Riferimento</span>
		<span style="display:none" class="ja">リファレンス</span>
		<span style="display:none" class="zh-CN">参考</span>
		<span style="display:none" class="zh-TW">參考資料</span>
	
	</a></li>
	<li id="resources-link"><a href="../../../resources/index.html" onClick="return loadLast('resources')">
	
		<span class="en">Resources</span>
		<span style="display:none" class="de"></span>
		<span style="display:none" class="es"></span>
		<span style="display:none" class="fr"></span>
		<span style="display:none" class="it"></span>
    		<span style="display:none" class="ja"></span>
		<span style="display:none" class="zh-CN"></span>
		<span style="display:none" class="zh-TW"></span>
	
	</a></li>
	<li id="videos-link"><a href="../../../videos/index.html" onClick="return loadLast('videos')">
	
		<span class="en">Videos</span>
		<span style="display:none" class="de"></span>
		<span style="display:none" class="es"></span>
		<span style="display:none" class="fr"></span>
		<span style="display:none" class="it"></span>
		<span style="display:none" class="ja">ビデオ</span>
		<span style="display:none" class="zh-CN"></span>
		<span style="display:none" class="zh-TW"></span>
	
	</a></li>
	<li><a href="http://android-developers.blogspot.com" onClick="return requestAppendHL(this.href)">
	
		<span class="en">Blog</span>
		<span style="display:none" class="de"></span>
		<span style="display:none" class="es"></span>
		<span style="display:none" class="fr"></span>
		<span style="display:none" class="it"></span>
		<span style="display:none" class="ja">ブログ</span>
		<span style="display:none" class="zh-CN">博客</span>
		<span style="display:none" class="zh-TW">網誌</span>
	
	</a></li>


     
</ul>
     
      </div>
      <div id="headerRight">
          <div id="headerLinks">
          
          <a href="http://www.android.com">Android.com</a>
          </div>
  <div id="search" >
      <div id="searchForm">
          <form accept-charset="utf-8" class="gsc-search-box" 
                onsubmit="return submit_search()">
            <table class="gsc-search-box" cellpadding="0" cellspacing="0"><tbody>
                <tr>
                  <td class="gsc-input">
                    <input id="search_autocomplete" class="gsc-input" type="text" size="33" autocomplete="off"
                      title="search developer docs" name="q"
                      value="search developer docs"
                      onFocus="search_focus_changed(this, true)"
                      onBlur="search_focus_changed(this, false)"
                      onkeydown="return search_changed(event, true, '../../../')"
                      onkeyup="return search_changed(event, false, '../../../')" />
                  <div id="search_filtered_div" class="no-display">
                      <table id="search_filtered" cellspacing=0>
                      </table>
                  </div>
                  </td>
                  <td class="gsc-search-button">
                    <input type="submit" value="Search" title="search" id="search-button" class="gsc-search-button" />
                  </td>
                  <td class="gsc-clear-button">
                    <div title="clear results" class="gsc-clear-button">&nbsp;</div>
                  </td>
                </tr></tbody>
              </table>
          </form>
      </div><!-- searchForm -->
  </div><!-- search -->
      </div><!-- headerRight -->
      <script type="text/javascript">
        <!--  
        changeTabLang(getLangPref());
        //-->
      </script>
  </div><!-- header -->

  <div class="g-section g-tpl-240" id="body-content">
    <div class="g-unit g-first" id="side-nav">
      <div id="devdoc-nav">
<ul>

  <li>
    <h2><span class="en">Android Basics</span>
        <span class="de" style="display:none">Einführung in Android</span>
        <span class="es" style="display:none">Información básica sobre Android</span>
        <span class="fr" style="display:none">Présentation d'Android</span>
        <span class="it" style="display:none">Nozioni di base su Android</span>
        <span class="ja" style="display:none">Android の基本</span>
        <span class="zh-CN" style="display:none">Android 基础知识</span>
        <span class="zh-TW" style="display:none">Android 簡介</span>
    </h2>
    <ul>
      <li><a href="../../../guide/basics/what-is-android.html">
        <span class="en">What Is Android?</span>
        <span class="de" style="display:none">Was ist Android?</span>
        <span class="es" style="display:none">¿Qué es Android?</span>
        <span class="fr" style="display:none">Qu'est-ce qu'Android&nbsp;?</span>
        <span class="it" style="display:none">Che cos'è Android?</span>
        <span class="ja" style="display:none">Android とは</span>
        <span class="zh-CN" style="display:none">Android 是什么？</span>
        <span class="zh-TW" style="display:none">什麼是 Android？</span>
          </a></li>
      <li><a href="../../../guide/topics/fundamentals.html">
        <span class="en">Application Fundamentals</span>
        <span class="de" style="display:none">Anwendungsgrundlagen</span>
        <span class="es" style="display:none">Fundamentos de las aplicaciones</span>
        <span class="fr" style="display:none">Principes de base des applications</span>
        <span class="it" style="display:none">Concetti fondamentali sulle applicazioni</span>
        <span class="ja" style="display:none">開発の基礎</span>
        <span class="zh-CN" style="display:none">应用程序基础</span>
        <span class="zh-TW" style="display:none">應用程式基本原理</span>
      </a></li>

  <!--  <li><a style="color:gray;">The Android SDK</a></li> -->
  <!--  <li><a style="color:gray;">Walkthrough for Developers</a></li> -->
      <!-- quick overview of what it's like to develop on Android -->
    </ul>
  </li>

  <li>
    <h2>
      <span class="en">Framework Topics</span>
      <span class="de" style="display:none">Framework-Themen</span>
      <span class="es" style="display:none">Temas sobre el framework</span>
      <span class="fr" style="display:none">Thèmes relatifs au framework</span>
      <span class="it" style="display:none">Argomenti relativi al framework</span>
      <span class="ja" style="display:none">フレームワーク トピック</span>
      <span class="zh-CN" style="display:none">框架主题</span>
      <span class="zh-TW" style="display:none">架構主題</span>
    </h2>
    <ul>
      <li class="toggle-list">
        <div><a href="../../../guide/topics/fundamentals/activities.html">
          <span class="en">Activities</span>
        </a></div>
        <ul>
          <li><a href="../../../guide/topics/fundamentals/fragments.html">
            <span class="en">Fragments</span>
          </a></li>
          <li><a href="../../../guide/topics/fundamentals/loaders.html">
            <span class="en">Loaders</span>
          </a></li>
          <li><a href="../../../guide/topics/fundamentals/tasks-and-back-stack.html">
            <span class="en">Tasks and Back Stack</span></a></li>
        </ul>
      </li>
      <li class="toggle-list">
        <div><a href="../../../guide/topics/fundamentals/services.html">
          <span class="en">Services</span>
        </a></div>
        <ul>
          <li><a href="../../../guide/topics/fundamentals/bound-services.html">
            <span class="en">Bound Services</span>
          </a></li>
        </ul>
      </li>
      <li><a href="../../../guide/topics/providers/content-providers.html">
            <span class="en">Content Providers</span>
          </a></li>
      <li><a href="../../../guide/topics/intents/intents-filters.html">
            <span class="en">Intents and Intent Filters</span>
          </a></li>
      <li><a href="../../../guide/topics/fundamentals/processes-and-threads.html">
            <span class="en">Processes and Threads</span>
          </a></li>
    </ul>


    <ul>
      <li class="toggle-list">
        <div><a href="../../../guide/topics/ui/index.html">
            <span class="en">User Interface</span>
          </a></div>
        <ul>
          <li><a href="../../../guide/topics/ui/declaring-layout.html">
               <span class="en">XML Layouts</span>
              </a></li>
          <li><a href="../../../guide/topics/ui/ui-events.html">
                <span class="en">Input Events</span>
              </a></li>
          <li><a href="../../../guide/topics/ui/menus.html">
               <span class="en">Menus</span>
              </a></li>
          <li><a href="../../../guide/topics/ui/actionbar.html">
               <span class="en">Action Bar</span>
              </a></li>
          <li><a href="../../../guide/topics/ui/dialogs.html">
                <span class="en">Dialogs</span>
              </a></li>
          <li class="toggle-list">
            <div><a href="../../../guide/topics/ui/notifiers/index.html">
                <span class="en">Notifications</span>
            </a></div>
            <ul>
              <li><a href="../../../guide/topics/ui/notifiers/toasts.html">
                <span class="en">Toast Notifications</span>
              </a></li>
              <li><a href="../../../guide/topics/ui/notifiers/notifications.html">
                <span class="en">Status Bar Notifications</span>
              </a></li>
            </ul>
          </li>
          <li><a href="../../../guide/topics/ui/drag-drop.html">
                <span class="en">Drag and Drop</span>
              </a></li>
          <li><a href="../../../guide/topics/ui/themes.html">
                <span class="en">Styles and Themes</span>
              </a></li>
          <li><a href="../../../guide/topics/ui/custom-components.html">
                <span class="en">Custom Components</span>
              </a></li>
          <li><a href="../../../guide/topics/ui/binding.html">
                <span class="en">Binding to Data with AdapterView</span>
              </a></li>
          <li><a href="../../../guide/topics/ui/layout-objects.html">
                <span class="en">Common Layout Objects</span>
              </a></li>
          <li><a href="../../../guide/topics/ui/how-android-draws.html">
                <span class="en">How Android Draws Views</span>
              </a></li>
        </ul>
      </li><!-- end of User Interface -->

      <li class="toggle-list">
        <div><a href="../../../guide/topics/resources/index.html">
               <span class="en">Application Resources</span>
             </a></div>
        <ul>
          <li><a href="../../../guide/topics/resources/providing-resources.html">
                <span class="en">Providing Resources</span>
              </a></li>
          <li><a href="../../../guide/topics/resources/accessing-resources.html">
                <span class="en">Accessing Resources</span>
              </a></li>
          <li><a href="../../../guide/topics/resources/runtime-changes.html">
                <span class="en">Handling Runtime Changes</span>
              </a></li>
          <li><a href="../../../guide/topics/resources/localization.html">
                <span class="en">Localization</span>
              </a></li>
          <li class="toggle-list">
            <div><a href="../../../guide/topics/resources/available-resources.html">
              <span class="en">Resource Types</span>
            </a></div>
            <ul>
              <li><a href="../../../guide/topics/resources/animation-resource.html">Animation</a></li>
              <li><a href="../../../guide/topics/resources/color-list-resource.html">Color State List</a></li>
              <li><a href="../../../guide/topics/resources/drawable-resource.html">Drawable</a></li>
              <li><a href="../../../guide/topics/resources/layout-resource.html">Layout</a></li>
              <li><a href="../../../guide/topics/resources/menu-resource.html">Menu</a></li>
              <li><a href="../../../guide/topics/resources/string-resource.html">String</a></li>
              <li><a href="../../../guide/topics/resources/style-resource.html">Style</a></li>
              <li><a href="../../../guide/topics/resources/more-resources.html">More Types</a></li>
            </ul>
          </li><!-- end of resource types -->
        </ul>
      </li><!-- end of app resources -->
      <li class="toggle-list">
        <div><a href="../../../guide/topics/data/data-storage.html">
            <span class="en">Data Storage</span>
          </a></div>
          <ul>
            <li><a href="../../../guide/topics/data/backup.html">
                <span class="en">Data Backup</span>
              </a>
            </li>
          </ul>
      </li>
      <li><a href="../../../guide/topics/security/security.html">
            <span class="en">Security and Permissions</span>
          </a></li>
      <li class="toggle-list">
        <div><a href="../../../guide/topics/manifest/manifest-intro.html">
          <span class="en">The AndroidManifest.xml File</span>
        </a></div>
        <ul>
          <li><a href="../../../guide/topics/manifest/action-element.html">&lt;action&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/activity-element.html">&lt;activity&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/activity-alias-element.html">&lt;activity-alias&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/application-element.html">&lt;application&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/category-element.html">&lt;category&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/compatible-screens-element.html">&lt;compatible-screens&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/data-element.html">&lt;data&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/grant-uri-permission-element.html">&lt;grant-uri-permission&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/instrumentation-element.html">&lt;instrumentation&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/intent-filter-element.html">&lt;intent-filter&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/manifest-element.html">&lt;manifest&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/meta-data-element.html">&lt;meta-data&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/path-permission-element.html">&lt;path-permission&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/permission-element.html">&lt;permission&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/permission-group-element.html">&lt;permission-group&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/permission-tree-element.html">&lt;permission-tree&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/provider-element.html">&lt;provider&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/receiver-element.html">&lt;receiver&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/service-element.html">&lt;service&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/supports-gl-texture-element.html">&lt;supports-gl-texture&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/supports-screens-element.html">&lt;supports-screens&gt;</a></li><!-- ##api level 4## -->
          <li><a href="../../../guide/topics/manifest/uses-configuration-element.html">&lt;uses-configuration&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/uses-feature-element.html">&lt;uses-feature&gt;</a></li> <!-- ##api level 4## -->
          <li><a href="../../../guide/topics/manifest/uses-library-element.html">&lt;uses-library&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/uses-permission-element.html">&lt;uses-permission&gt;</a></li>
          <li><a href="../../../guide/topics/manifest/uses-sdk-element.html">&lt;uses-sdk&gt;</a></li>
        </ul>
      </li><!-- end of the manifest file -->
    </ul>

    <ul>
    <li class="toggle-list">
        <div><a href="../../../guide/topics/graphics/index.html">
            <span class="en">Graphics</span>
          </a><span class="new-child">new!</span></div>
        <ul>
          <li><a href="../../../guide/topics/graphics/2d-graphics.html">
              <span class="en">Canvas and Drawables</span></a></li>
          <li><a href="../../../guide/topics/graphics/hardware-accel.html">
              <span class="en">Hardware Acceleration</span></a>
            <span class="new">new!</span></li>
          <li><a href="../../../guide/topics/graphics/opengl.html">
              <span class="en">OpenGL</span>
            </a><span class="new">updated</span></li>
        </ul>
      </li>
      <li class="toggle-list">
        <div><a href="../../../guide/topics/graphics/animation.html">
            <span class="en">Animation</span>
          </a></div>
        <ul>
          <li><a href="../../../guide/topics/graphics/prop-animation.html">
              <span class="en">Property Animation</span></a></li>
          <li><a href="../../../guide/topics/graphics/view-animation.html">
              <span class="en">View Animation</span></a></li>
          <li><a href="../../../guide/topics/graphics/drawable-animation.html">
              <span class="en">Drawable Animation</span></a></li>
        </ul>
      </li>
      <li class="toggle-list">
	        <div><a href="../../../guide/topics/renderscript/index.html">
	            <span class="en">RenderScript</span>
	          </a></div>
	        <ul>
	          <li><a href="../../../guide/topics/renderscript/graphics.html">
	                <span class="en">Graphics</span>
	              </a>
	          </li>
	          <li><a href="../../../guide/topics/renderscript/compute.html">
	                <span class="en">Compute</span>
	              </a>
	          </li>
	        </ul>
  	  </li>

      <li class="toggle-list">
          <div><a href="../../../guide/topics/media/index.html">
            <span class="en">Multimedia and Camera</span>
          </a><span class="new">updated</span></div>
          <ul>
            <li><a href="../../../guide/topics/media/mediaplayer.html">
                  <span class="en">Media Playback</span></a>
                </li>
            <li><a href="../../../guide/topics/media/jetplayer.html">
                  <span class="en">JetPlayer</span></a>
                </li>
            <li><a href="../../../guide/topics/media/camera.html">
                  <span class="en">Camera</span></a>
                  <span class="new">new!</span>
                </li>
            <li><a href="../../../guide/topics/media/audio-capture.html">
                  <span class="en">Audio Capture</span></a>
                </li>
          </ul>
      </li>
      <li>
        <a href="../../../guide/topics/clipboard/copy-paste.html">
            <span class="en">Copy and Paste</span>
        </a></li>
  <!--<li class="toggle-list">
        <div><a style="color:gray;">Sensors</a></div>
          <ul>
            <li><a style="color:gray;">Camera</a></li>
            <li><a style="color:gray;">Compass</a></li>
            <li><a style="color:gray;">Accelerometer</a></li>
          </ul>
      </li> -->
      <li class="toggle-list">
        <div><a href="../../../guide/topics/location/index.html">
               <span class="en">Location and Maps</span>
             </a></div>
        <ul>
          <li><a href="../../../guide/topics/location/obtaining-user-location.html">
                <span class="en">Obtaining User Location</span>
              </a></li>
        </ul>
      </li>
  <!--<li class="toggle-list">
        <div><a style="color:gray;">Wireless Controls</a></div>
          <ul>
            <li><a style="color:gray;">Wi-Fi</a></li>
          </ul>
      </li> -->
  <!--<li><a style="color:gray;">Localization</a></li>  -->
      <li><a href="../../../guide/topics/appwidgets/index.html">
            <span class="en">App Widgets</span></a>
          </li>
      <li><a href="../../../guide/topics/wireless/bluetooth.html">
            <span class="en">Bluetooth</span></a>
          </li>
      <li><a href="../../../guide/topics/nfc/index.html">
            <span class="en">Near Field Communication</span>
          </a></li>
      <li class="toggle-list">
          <div><a href="../../../guide/topics/usb/index.html">
            <span class="en">USB</span></a>
          </div>
            <ul>
              <li><a href="../../../guide/topics/usb/accessory.html">Accessory</a></li>
              <li><a href="../../../guide/topics/usb/host.html">Host</a></li>
              <li><a href="../../../guide/topics/usb/adk.html">Open Accessory Dev Kit</a></li>
            </ul>
          </li>

       <li><a href="../../../guide/topics/network/sip.html">
            <span class="en">Session Initiation Protocol</span>
          </a></li>
      <li class="toggle-list">
        <div><a href="../../../guide/topics/search/index.html">
            <span class="en">Search</span>
          </a></div>
          <ul>
            <li><a href="../../../guide/topics/search/search-dialog.html">Creating a Search Interface</a></li>
            <li><a href="../../../guide/topics/search/adding-recent-query-suggestions.html">Adding Recent Query Suggestions</a></li>
            <li><a href="../../../guide/topics/search/adding-custom-suggestions.html">Adding Custom Suggestions</a></li>
            <li><a href="../../../guide/topics/search/searchable-config.html">Searchable Configuration</a></li>
          </ul>
      </li>
      <li><a href="../../../guide/topics/admin/device-admin.html">
            <span class="en">Device Administration</span></a>
      </li>
      <li class="toggle-list">
           <div>
                <a href="../../../guide/topics/testing/index.html">
                   <span class="en">Testing</span>
               </a>
           </div>
           <ul>
              <li>
                <a href="../../../guide/topics/testing/testing_android.html">
                <span class="en">Testing Fundamentals</span></a>
              </li>
              <li>
                <a href="../../../guide/topics/testing/activity_testing.html">
                <span class="en">Activity Testing</span></a>
              </li>
              <li>
                <a href="../../../guide/topics/testing/contentprovider_testing.html">
                <span class="en">Content Provider Testing</span></a>
              </li>
              <li>
                <a href="../../../guide/topics/testing/service_testing.html">
                <span class="en">Service Testing</span></a>
              </li>
              <li>
                <a href="../../../guide/topics/testing/what_to_test.html">
                <span class="en">What To Test</span></a>
              </li>
           </ul>
      </li>
    </ul>
  </li>

  <li>
    <h2>
      <span class="en">Android Market Topics</span>
    </h2>
    <ul>
      <li><a href="../../../guide/publishing/licensing.html">
          <span class="en">Application Licensing</span></a>
      </li>
      <li class="toggle-list">
        <div><a href="../../../guide/market/billing/index.html">
            <span class="en">In-app Billing</span></a>
        </div>
        <ul>
          <li><a href="../../../guide/market/billing/billing_overview.html">
              <span class="en">In-app Billing Overview</span></a>
          </li>
          <li><a href="../../../guide/market/billing/billing_integrate.html">
              <span class="en">Implementing In-app Billing</span></a>
          </li>
          <li><a href="../../../guide/market/billing/billing_best_practices.html">
              <span class="en">Security and Design</span></a>
          </li>
          <li><a href="../../../guide/market/billing/billing_testing.html">
              <span class="en">Testing In-app Billing</span></a>
          </li>
          <li><a href="../../../guide/market/billing/billing_admin.html">
              <span class="en">Administering In-app Billing</span></a>
          </li>
          <li><a href="../../../guide/market/billing/billing_reference.html">
              <span class="en">In-app Billing Reference</span></a>
          </li>
        </ul>
      </li>
      <li><a href="../../../guide/appendix/market-filters.html">
          <span class="en">Market Filters</span></a>
      </li>
      <li><a href="../../../guide/market/publishing/multiple-apks.html">
          <span class="en">Multiple APK Support</span></a>
      </li>
    </ul>
  </li>


  <li>
    <h2><span class="en">Developing</span>
               <span class="de" style="display:none">Entwicklung</span>
               <span class="es" style="display:none">Desarrollo</span>
               <span class="fr" style="display:none">Développement</span>
               <span class="it" style="display:none">Sviluppo</span>
               <span class="ja" style="display:none">開発</span>
               <span class="zh-CN" style="display:none">开发</span>
               <span class="zh-TW" style="display:none">開發</span>
    </h2>
    <ul>
  <!--<li><a href="">Developing for Android</a></li>
      signing, upgrading, selecting a package name, select device profile, touch, trackball, dpad available, etc. -->
      <li>
        <a href="../../../guide/developing/index.html">
        <span class="en">Introduction</span></a>
      </li>

      <li class="toggle-list">
        <div>
           <a href="../../../guide/developing/devices/index.html">
                <span class="en">Managing Virtual Devices</span>
            </a>
        </div>
        <ul>
          <li>
            <a href="../../../guide/developing/devices/managing-avds.html">
              <span class="en">With AVD Manager</span>
            </a>
          </li>
          <li>
            <a href="../../../guide/developing/devices/managing-avds-cmdline.html">
              <span class="en">From the Command Line</span>
            </a>
          </li>
          <li>
           <a href="../../../guide/developing/devices/emulator.html">
                <span class="en">Using the Android Emulator</span>
            </a>
          </li>
        </ul>
      </li>
      <li>
        <a href="../../../guide/developing/device.html">
          <span class="en">Using Hardware Devices</span>
        </a>
      </li>

      <li class="toggle-list">
        <div>
          <a href="../../../guide/developing/projects/index.html">
            <span class="en">Managing Projects</span>
          </a>
        </div>
        <ul>
          <li>
            <a href="../../../guide/developing/projects/projects-eclipse.html">
              <span class="en">From Eclipse with ADT</span>
            </a>
          </li>
          <li>
            <a href="../../../guide/developing/projects/projects-cmdline.html">
                <span class="en">From the Command Line</span>
            </a>
          </li>
        </ul>
      </li>

      <li class="toggle-list">
        <div>
          <a href="../../../guide/developing/building/index.html">
            <span class="en">Building and Running</span>
          </a>
        </div>
        <ul>
          <li><a href="../../../guide/developing/building/building-eclipse.html">
            <span class="en">From Eclipse with ADT</span>
          </a></li>
          <li><a href="../../../guide/developing/building/building-cmdline.html">
            <span class="en">From the Command Line</span></a></li>
        </ul>
      </li>

      <li class="toggle-list">
        <div>
          <a href="../../../guide/developing/debugging/index.html">
            <span class="en">Debugging</span>
          </a>
        </div>
        <ul>
          <li>
            <a href="../../../guide/developing/debugging/debugging-projects.html">
                <span class="en">From Eclipse with ADT</span>
            </a>
          </li>
          <li>
            <a href="../../../guide/developing/debugging/debugging-projects-cmdline.html">
                <span class="en">From Other IDEs</span>
            </a>
          </li>
          <li>
            <a href="../../../guide/developing/debugging/ddms.html">
              <span class="en">Using DDMS</span>
            </a>
          </li>
          <li>
            <a href="../../../guide/developing/debugging/debugging-log.html">
                <span class="en">Reading and Writing Logs</span>
            </a>
          </li>
          <li>
            <a href="../../../guide/developing/debugging/debugging-ui.html">
                <span class="en">Debugging and Profiling UIs</span>
            </a>
          </li>
          <li>
            <a href="../../../guide/developing/debugging/debugging-tracing.html">
                <span class="en">Profiling with Traceview and dmtracedump</span>
            </a>
          </li>
          <li>
            <a href="../../../guide/developing/debugging/debugging-devtools.html">
                <span class="en">Using the Dev Tools App</span>
            </a>
          </li>
        </ul>
      </li>

      <li class="toggle-list">
           <div>
                <a href="../../../guide/developing/testing/index.html">
                   <span class="en">Testing</span>
               </a>
           </div>
           <ul>
              <li>
                <a href="../../../guide/developing/testing/testing_eclipse.html">
                  <span class="en">From Eclipse with ADT</span>
                </a>
              </li>

              <li>
                <a href="../../../guide/developing/testing/testing_otheride.html">
                  <span class="en">From Other IDEs</span>
                </a>
              </li>
           </ul>
         </li>

         <li class="toggle-list">
        <div><a href="../../../guide/developing/tools/index.html">
            <span class="en">Tools</span>
          </a></div>
        <ul>
          <li><a href="../../../guide/developing/tools/adb.html">adb</a></li>
          <li><a href="../../../guide/developing/tools/adt.html">ADT</a></li>
          <li><a href="../../../guide/developing/tools/android.html">android</a></li>
          <li><a href="../../../guide/developing/tools/bmgr.html">bmgr</a>
          <li><a href="../../../guide/developing/tools/dmtracedump.html">dmtracedump</a></li>
          <li><a href="../../../guide/developing/tools/draw9patch.html">Draw
          9-Patch</a></li>
          <li><a href="../../../guide/developing/tools/emulator.html">Emulator</a></li>
          <li><a href="../../../guide/developing/tools/etc1tool.html">etc1tool</a></li>
          <li><a href="../../../guide/developing/tools/hierarchy-viewer.html">Hierarchy Viewer</a></li>
          <li><a href="../../../guide/developing/tools/hprof-conv.html">hprof-conv</a></li>
          <li><a href="../../../guide/developing/tools/layoutopt.html">layoutopt</a></li>
          <li><a href="../../../guide/developing/tools/logcat.html">logcat</a></li>
          <li><a href="../../../guide/developing/tools/mksdcard.html">mksdcard</a></li>
          <li><a href="../../../guide/developing/tools/monkey.html">Monkey</a></li>
          <li class="toggle-list">
            <div><a href="../../../guide/developing/tools/monkeyrunner_concepts.html">
              <span class="en">monkeyrunner</span>
            </a></div>
            <ul>
              <li><a href="../../../guide/developing/tools/MonkeyDevice.html">
                <span class="en">MonkeyDevice</span>
                </a></li>
              <li><a href="../../../guide/developing/tools/MonkeyImage.html">
                <span class="en">MonkeyImage</span>
                </a></li>
              <li><a href="../../../guide/developing/tools/MonkeyRunner.html">
                <span class="en">MonkeyRunner</span>
                </a></li>
            </ul>
          </li>
          <li><a href="../../../guide/developing/tools/proguard.html">ProGuard</a></li>
          <li><a href="../../../guide/developing/tools/adb.html#sqlite">sqlite3</a></li>
          <li><a href="../../../guide/developing/tools/traceview.html">Traceview</a></li>
          <li><a href="../../../guide/developing/tools/zipalign.html">zipalign</a></li>
        </ul>
      </li>
    </ul>
  </li>

  <li>
    <h2><span class="en">Publishing</span>
        <span class="de" style="display:none">Veröffentlichung</span>
        <span class="es" style="display:none">Publicación</span>
        <span class="fr" style="display:none">Publication</span>
        <span class="it" style="display:none">Pubblicazione</span>
        <span class="ja" style="display:none">公開</span>
        <span class="zh-CN" style="display:none">发布</span>
        <span class="zh-TW" style="display:none">發佈</span>
    </h2>
    <ul>
      <li><a href="../../../guide/publishing/app-signing.html">
            <span class="en">Signing Your Applications</span>
            <span class="de" style="display:none">Signieren Ihrer Anwendungen</span>
            <span class="es" style="display:none">Firma de aplicaciones</span>
            <span class="fr" style="display:none">Attribution de votre signature <br />à vos applications</span>
            <span class="it" style="display:none">Firma delle applicazioni</span>
            <span class="ja" style="display:none">アプリケーションへの署名</span>
            <span class="zh-CN" style="display:none">应用程序签名</span>
            <span class="zh-TW" style="display:none">簽署應用程式</span>
          </a></li>
      <li><a href="../../../guide/publishing/versioning.html">
            <span class="en">Versioning Your Applications</span>
            <span class="de" style="display:none">Versionsverwaltung für Ihre <br />Anwendungen</span>
            <span class="es" style="display:none">Versiones de las aplicaciones</span>
            <span class="fr" style="display:none">Attribution d'une version à vos applications</span>
            <span class="it" style="display:none">Controllo versioni delle applicazioni</span>
            <span class="ja" style="display:none">アプリケーションのバージョニング</span>
            <span class="zh-CN" style="display:none">应用程序版本控制</span>
            <span class="zh-TW" style="display:none">應用程式版本設定</span>
          </a></li>
      <li><a href="../../../guide/publishing/preparing.html">
            <span class="en">Preparing to Publish</span>
            <span class="de" style="display:none">Vorbereitung auf die Veröffentlichung</span>
            <span class="es" style="display:none">Publicación de aplicaciones</span>
            <span class="fr" style="display:none">Préparation à la publication</span>
            <span class="it" style="display:none">Preparativi per la pubblicazione</span>
            <span class="ja" style="display:none">公開の準備</span>
            <span class="zh-CN" style="display:none">准备发布</span>
            <span class="zh-TW" style="display:none">準備發佈</span>
          </a></li>
      <li><a href="../../../guide/publishing/publishing.html">
            <span class="en">Publishing on Android Market</span>
          </a></li>
    </ul>
  </li>

  <li>
    <h2><span class="en">Best Practices</span>
               <span class="de" style="display:none">Bewährte Verfahren</span>
               <span class="es" style="display:none">Prácticas recomendadas</span>
               <span class="fr" style="display:none">Meilleures pratiques</span>
               <span class="it" style="display:none">Best practice</span>
               <span class="ja" style="display:none">ベスト プラクティス</span>
               <span class="zh-CN" style="display:none">最佳实践</span>
               <span class="zh-TW" style="display:none">最佳實務</span>
    </h2>
    <ul>
      <li><a href="../../../guide/practices/compatibility.html">
            <span class="en">Compatibility</span>
          </a></li>
      <li class="toggle-list">
        <div><a href="../../../guide/practices/screens_support.html">
          <span class="en">Supporting Multiple Screens</span>
        </a></div>
        <ul>
          <li><a href="../../../guide/practices/screens-distribution.html">
            <span class="en">Distributing to Specific Screens</span>
          </a></li>
          <li><a href="../../../guide/practices/screen-compat-mode.html">
            <span class="en">Screen Compatibility Mode</span>
          </a></li>
          <li><a href="../../../guide/practices/screens-support-1.5.html">
            <span class="en">Strategies for Android 1.5</span>
          </a></li>
        </ul>
      </li>
      <li><a href="../../../guide/practices/optimizing-for-3.0.html">
            <span class="en">Optimizing Apps for Android 3.0</span>
          </a></li>
      <li class="toggle-list">
        <div><a href="../../../guide/practices/ui_guidelines/index.html">
               <span class="en">UI Guidelines</span>
             </a></div>
        <ul>
          <li class="toggle-list">
            <div><a href="../../../guide/practices/ui_guidelines/icon_design.html">
                   <span class="en">Icon Design <span class="new">updated</span></span>
                 </a></div>
            <ul>
              <li><a href="../../../guide/practices/ui_guidelines/icon_design_launcher.html">
                    <span class="en">Launcher Icons <span class="new">updated</span></span>
                  </a></li>
              <li><a href="../../../guide/practices/ui_guidelines/icon_design_menu.html">
                    <span class="en">Menu Icons</span>
                  </a></li>
              <li><a href="../../../guide/practices/ui_guidelines/icon_design_action_bar.html">
                    <span class="en">Action Bar Icons <span class="new">new!</span></span>
                  </a></li>
              <li><a href="../../../guide/practices/ui_guidelines/icon_design_status_bar.html">
                    <span class="en">Status Bar Icons <span class="new">updated</span></span>
                  </a></li>
              <li><a href="../../../guide/practices/ui_guidelines/icon_design_tab.html">
                    <span class="en">Tab Icons</span>
                  </a></li>
              <li><a href="../../../guide/practices/ui_guidelines/icon_design_dialog.html">
                    <span class="en">Dialog Icons</span>
                  </a></li>
              <li><a href="../../../guide/practices/ui_guidelines/icon_design_list.html">
                    <span class="en">List View Icons</span>
                  </a></li>
            </ul>
          </li>
          <li><a href="../../../guide/practices/ui_guidelines/widget_design.html">
                <span class="en">App Widget Design <span class="new">updated</span></span>
              </a></li>
          <li><a href="../../../guide/practices/ui_guidelines/activity_task_design.html">
                <span class="en">Activity and Task Design</span>
              </a></li>
          <li><a href="../../../guide/practices/ui_guidelines/menu_design.html">
                <span class="en">Menu Design</span>
              </a></li>
        </ul>
      </li>
      </ul>
      <ul>
      <li><a href="../../../guide/practices/design/accessibility.html">
            <span class="en">Designing for Accessibility</span>
          </a></li>
      <li class="toggle-list">
        <div><a href="../../../guide/practices/design/performance.html">
            <span class="en">Designing for Performance</span>
          </a></div>
        <ul>
          <li><a href="../../../guide/practices/design/jni.html">
                <span class="en">JNI Tips</span>
              </a></li>
        </ul>
      </li>
      <li><a href="../../../guide/practices/design/responsiveness.html">
            <span class="en">Designing for Responsiveness</span>
          </a></li>
      <li><a href="../../../guide/practices/design/seamlessness.html">
            <span class="en">Designing for Seamlessness</span>
          </a></li>
    </ul>
  </li>

  <li>
    <h2><span class="en">Web Applications</span>
    </h2>
    <ul>
      <li><a href="../../../guide/webapps/index.html">
            <span class="en">Web Apps Overview</span>
          </a></li>
      <li><a href="../../../guide/webapps/targeting.html">
            <span class="en">Targeting Screens from Web Apps</span>
          </a></li>
      <li><a href="../../../guide/webapps/webview.html">
            <span class="en">Building Web Apps in WebView</span>
          </a></li>
      <li><a href="../../../guide/webapps/debugging.html">
            <span class="en">Debugging Web Apps</span>
          </a></li>
      <li><a href="../../../guide/webapps/best-practices.html">
            <span class="en">Best Practices for Web Apps</span>
          </a></li>
    </ul>
  </li>

  <li>
    <h2><span class="en">Appendix</span>
               <span class="de" style="display:none">Anhang</span>
               <span class="es" style="display:none">Apéndice</span>
               <span class="fr" style="display:none">Annexes</span>
               <span class="it" style="display:none">Appendice</span>
               <span class="ja" style="display:none">付録</span>
               <span class="zh-CN" style="display:none">附录</span>
               <span class="zh-TW" style="display:none">附錄</span>
    </h2>
    <ul>
      <li><a href="../../../guide/appendix/api-levels.html">
            <span class="en">Android API Levels</span>
          </a></li>
      <li><a href="../../../guide/appendix/install-location.html">
            <span class="en">App Install Location</span>
          </a></li>
      <li><a href="../../../guide/appendix/media-formats.html">
            <span class="en">Supported Media Formats <span class="new">updated</span></span>
          </a></li>
      <li><a href="../../../guide/appendix/g-app-intents.html">
            <span class="en">Intents List: Google Apps</span>
          </a></li>
      <li><a href="../../../guide/developing/tools/aidl.html">AIDL</a></li>
      <li><a href="../../../guide/appendix/glossary.html">
            <span class="en">Glossary</span>
          </a></li>
    </ul>
  </li>

</ul>

<script type="text/javascript">
<!--
    buildToggleLists();
    changeNavLang(getLangPref());
//-->
</script>

      </div>
    </div> <!-- end side-nav -->
    <script>
      addLoadEvent(function() {
        scrollIntoView("devdoc-nav");
        });
    </script>




<div class="g-unit" id="doc-content"><a name="top"></a>

<div id="jd-header" class="guide-header">
  <span class="crumb">
    &nbsp;
    
  </span>
<h1>Security and Permissions</h1>
</div>

  <div id="jd-content">

    <div class="jd-descr">
    <div id="qv-wrapper">
<div id="qv">

<h2>In this document</h2>
<ol>
<li><a href="#arch">Security Architecture</a></li>
<li><a href="#signing">Application Signing</a></li>
<li><a href="#userid">User IDs and File Access</a></li>
<li><a href="#permissions">Using Permissions</a></li>
<li><a href="#declaring">Declaring and Enforcing Permissions</a>
	<ol>
	<li><a href="#manifest">...in AndroidManifest.xml</a></li>
	<li><a href="#broadcasts">...when Sending Broadcasts</a></li>
	<li><a href="#enforcement">Other Permission Enforcement</a></li>
	</ol></li>
<li><a href="#uri">URI Permissions</a></li>
</ol>
</div>
</div>
<p>This document describes how application developers can use the
security features provided by Android.  A more general <a
href="http://source.android.com/tech/security/index.html"> Android Security
Overview</a> is provided in the Android Open Source Project.</p>

<p>Android is a privilege-separated operating system, in which each
application runs with a distinct system identity (Linux user ID and group
ID).  Parts of the system are also separated into distinct identities.
Linux thereby isolates applications from each other and from the system.</p>

<p>Additional finer-grained security features are provided through a
"permission" mechanism that enforces restrictions on the specific operations
that a particular process can perform, and per-URI permissions for granting
ad-hoc access to specific pieces of data.</p>

<a name="arch"></a>
<h2>Security Architecture</h2>

<p>A central design point of the Android security architecture is that no
application, by default, has permission to perform any operations that would
adversely impact other applications, the operating system, or the user.  This
includes reading or writing the user's private data (such as contacts or
e-mails), reading or writing another application's files, performing
network access, keeping the device awake, etc.</p>

<p>Because Android sandboxes applications from each other, applications
must explicitly share resources and data. They do this by declaring the
<em>permissions</em> they need for additional capabilities not provided by
the basic sandbox. Applications statically declare the permissions they
require, and the Android system prompts the user for consent at the time the
application is installed. Android has no mechanism for granting permissions
dynamically (at run-time) because it complicates the user experience to the
detriment of security.</p>

<p>The application sandbox does not depend on the technology used to build
an application. In particular the Dalvik VM is not a security boundary, and
any app can run native code (see <a href="/sdk/ndk/index.html">the Android
NDK</a>). All types of applications &mdash; Java, native, and hybrid &mdash;
are sandboxed in the same way and have the same degree of security from each
other.</p>

<a name="signing"></a>
<h2>Application Signing</h2>

<p>All Android applications (.apk files) must be signed with a certificate
whose private key is held by their developer.  This certificate identifies
the author of the application.  The certificate does <em>not</em> need to be
signed by a certificate authority: it is perfectly allowable, and typical,
for Android applications to use self-signed certificates. The purpose of
certificates in Android is to distinguish application authors. This allows
the system to grant or deny applications access to <a
href="/guide/topics/manifest/permission-element.html#plevel">signature-level
permissions</a> and to grant or deny an application's <a
href="/guide/topics/manifest/manifest-element.html#uid">request to be given
the same Linux identity</a> as another application.</p>

<a name="userid"></a>
<h2>User IDs and File Access</h2>

<p>At install time, Android gives each package a distinct Linux user ID. The
identity remains constant for the duration of the package's life on that
device. On a different device, the same package may have a different UID;
what matters is that each package has a distinct UID on a given device.</p>

<p>Because security enforcement happens at the
process level, the code of any two packages can not normally
run in the same process, since they need to run as different Linux users.
You can use the <code><a href="../../../reference/android/R.attr.html#sharedUserId">sharedUserId</a></code> attribute in the
<code>AndroidManifest.xml</code>'s
<code><a href="../../../reference/android/R.styleable.html#AndroidManifest">manifest</a></code> tag of each package to
have them assigned the same user ID.  By doing this, for purposes of security
the two packages are then treated as being the same application, with the same
user ID and file permissions.  Note that in order to retain security, only two applications
signed with the same signature (and requesting the same sharedUserId) will
be given the same user ID.</p>

<p>Any data stored by an application will be assigned that application's user
ID, and not normally accessible to other packages.  When creating a new file
with <code><a href="../../../reference/android/content/Context.html#getSharedPreferences(java.lang.String, int)">getSharedPreferences(String, int)</a></code>,
<code><a href="../../../reference/android/content/Context.html#openFileOutput(java.lang.String, int)">openFileOutput(String, int)</a></code>, or
<code><a href="../../../reference/android/content/Context.html#openOrCreateDatabase(java.lang.String, int, android.database.sqlite.SQLiteDatabase.CursorFactory)">openOrCreateDatabase(String, int, SQLiteDatabase.CursorFactory)</a></code>,
you can use the
<code><a href="../../../reference/android/content/Context.html#MODE_WORLD_READABLE">MODE_WORLD_READABLE</a></code> and/or
<code><a href="../../../reference/android/content/Context.html#MODE_WORLD_WRITEABLE">MODE_WORLD_WRITEABLE</a></code> flags to allow any other
package to read/write the file.  When setting these flags, the file is still
owned by your application, but its global read and/or write permissions have
been set appropriately so any other application can see it.</p>


<a name="permissions"></a>
<h2>Using Permissions</h2>

<p>A basic Android application has no permissions associated with it,
meaning it can not do anything that would adversely impact the user experience
or any data on the device.  To make use of protected features of the device,
you must include in your <code>AndroidManifest.xml</code> one or more
<code><code><a href="../../../reference/android/R.styleable.html#AndroidManifestUsesPermission">&lt;uses-permission&gt;</a></code></code>
tags declaring the permissions that your application needs.</p>

<p>For example, an application that needs to monitor incoming SMS messages would
specify:</p>

<pre>&lt;manifest xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
    package=&quot;com.android.app.myapp&quot; &gt;
    &lt;uses-permission android:name=&quot;android.permission.RECEIVE_SMS&quot; /&gt;
    ...
&lt;/manifest&gt;</pre>

<p>At application install time, permissions requested by the application are
granted to it by the package installer, based on checks against the
signatures of the applications declaring those permissions and/or interaction
with the user. <em>No</em> checks with the user
are done while an application is running: it either was granted a particular
permission when installed, and can use that feature as desired, or the
permission was not granted and any attempt to use the feature will fail
without prompting the user.</p>

<p>Often times a permission failure will result in a <code><a href="../../../reference/java/lang/SecurityException.html">SecurityException</a></code> being thrown back to the application. However,
this is not guaranteed to occur everywhere. For example, the <code><a href="../../../reference/android/content/Context.html#sendBroadcast(android.content.Intent)">sendBroadcast(Intent)</a></code> method checks permissions as data is
being delivered to each receiver, after the method call has returned, so you
will not receive an exception if there are permission failures. In almost all
cases, however, a permission failure will be printed to the system log.</p>

<p>The permissions provided by the Android system can be found at <code><a href="../../../reference/android/Manifest.permission.html">Manifest.permission</a></code>. Any application may also define and enforce its
own permissions, so this is not a comprehensive list of all possible
permissions.</p>

<p>A particular permission may be enforced at a number of places during your
program's operation:</p>

<ul>
<li>At the time of a call into the system, to prevent an application from
executing certain functions.</li>
<li>When starting an activity, to prevent applications from launching
activities of other applications.</li>
<li>Both sending and receiving broadcasts, to control who can receive
your broadcast or who can send a broadcast to you.</li>
<li>When accessing and operating on a content provider.</li>
<li>Binding to or starting a service.</li>
</ul>


<a name="declaring"></a>
<h2>Declaring and Enforcing Permissions</h2>

<p>To enforce your own permissions, you must first declare them in your
<code>AndroidManifest.xml</code> using one or more
<code><code><a href="../../../reference/android/R.styleable.html#AndroidManifestPermission">&lt;permission&gt;</a></code></code>
tags.</p>

<p>For example, an application that wants to control who can start one
of its activities could declare a permission for this operation as follows:</p>

<pre>&lt;manifest xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
    package=&quot;com.me.app.myapp&quot; &gt;
    &lt;permission android:name=&quot;com.me.app.myapp.permission.DEADLY_ACTIVITY&quot;
        android:label=&quot;&#64;string/permlab_deadlyActivity&quot;
        android:description=&quot;&#64;string/permdesc_deadlyActivity&quot;
        android:permissionGroup=&quot;android.permission-group.COST_MONEY&quot;
        android:protectionLevel=&quot;dangerous&quot; /&gt;
    ...
&lt;/manifest&gt;</pre>

<p>The <code><a href="../../../reference/android/R.styleable.html#AndroidManifestPermission_protectionLevel">&lt;protectionLevel&gt;</a></code> attribute is required, telling the system how the
user is to be informed of applications requiring the permission, or who is
allowed to hold that permission, as described in the linked documentation.</p>

<p>The <code><a href="../../../reference/android/R.styleable.html#AndroidManifestPermission_permissionGroup">&lt;permissionGroup&gt;</a></code> attribute is optional, and only used to help the system display
permissions to the user.  You will usually want to set this to either a standard
system group (listed in <code><a href="../../../reference/android/Manifest.permission_group.html">android.Manifest.permission_group</a></code>) or in more rare cases to one defined by
yourself.  It is preferred to use an existing group, as this simplifies the
permission UI shown to the user.</p>

<p>Note that both a label and description should be supplied for the
permission. These are string resources that can be displayed to the user when
they are viewing a list of permissions
(<code><code><a href="../../../reference/android/R.styleable.html#AndroidManifestPermission_label">android:label</a></code></code>)
or details on a single permission (
<code><code><a href="../../../reference/android/R.styleable.html#AndroidManifestPermission_description">android:description</a></code></code>).
The label should be short, a few words
describing the key piece of functionality the permission is protecting. The
description should be a couple sentences describing what the permission allows
a holder to do. Our convention for the description is two sentences, the first
describing the permission, the second warning the user of what bad things
can happen if an application is granted the permission.</p>

<p>Here is an example of a label and description for the CALL_PHONE
permission:</p>

<pre>
    &lt;string name=&quot;permlab_callPhone&quot;&gt;directly call phone numbers&lt;/string&gt;
    &lt;string name=&quot;permdesc_callPhone&quot;&gt;Allows the application to call
        phone numbers without your intervention. Malicious applications may
        cause unexpected calls on your phone bill. Note that this does not
        allow the application to call emergency numbers.&lt;/string&gt;
</pre>

<p>You can look at the permissions currently defined in the system with the
Settings app and the shell command <code>adb shell pm list permissions</code>.
To use the Settings app, go to Settings &gt; Applications.  Pick an app and
scroll down to see the permissions that the app uses. For developers, the adb '-s'
option displays the permissions in a form similar to how the user will see them:</p>

<pre>
$ adb shell pm list permissions -s
All Permissions:

Network communication: view Wi-Fi state, create Bluetooth connections, full
Internet access, view network state

Your location: access extra location provider commands, fine (GPS) location,
mock location sources for testing, coarse (network-based) location

Services that cost you money: send SMS messages, directly call phone numbers

...</pre>

<a name="manifest"></a>
<h3>Enforcing Permissions in AndroidManifest.xml</h3>

<p>High-level permissions restricting access to entire components of the
system or application can be applied through your
<code>AndroidManifest.xml</code>. All that this requires is including an <code><a href="../../../reference/android/R.attr.html#permission">android:permission</a></code> attribute on the desired
component, naming the permission that will be used to control access to
it.</p>

<p><strong><code><a href="../../../reference/android/app/Activity.html">Activity</a></code></strong> permissions
(applied to the
<code><a href="../../../reference/android/R.styleable.html#AndroidManifestActivity">&lt;activity&gt;</a></code> tag)
restrict who can start the associated
activity.  The permission is checked during
<code><a href="../../../reference/android/content/Context.html#startActivity(android.content.Intent)">Context.startActivity()</a></code> and
<code><a href="../../../reference/android/app/Activity.html#startActivityForResult(android.content.Intent, int)">Activity.startActivityForResult()</a></code>;
if the caller does not have
the required permission then <code><a href="../../../reference/java/lang/SecurityException.html">SecurityException</a></code> is thrown
from the call.</p>

<p><strong><code><a href="../../../reference/android/app/Service.html">Service</a></code></strong> permissions
(applied to the
<code><a href="../../../reference/android/R.styleable.html#AndroidManifestService">&lt;service&gt;</a></code> tag)
restrict who can start or bind to the
associated service.  The permission is checked during
<code><a href="../../../reference/android/content/Context.html#startService(android.content.Intent)">Context.startService()</a></code>,
<code><a href="../../../reference/android/content/Context.html#stopService(android.content.Intent)">Context.stopService()</a></code> and
<code><a href="../../../reference/android/content/Context.html#bindService(android.content.Intent, android.content.ServiceConnection, int)">Context.bindService()</a></code>;
if the caller does not have
the required permission then <code><a href="../../../reference/java/lang/SecurityException.html">SecurityException</a></code> is thrown
from the call.</p>

<p><strong><code><a href="../../../reference/android/content/BroadcastReceiver.html">BroadcastReceiver</a></code></strong> permissions
(applied to the
<code><a href="../../../reference/android/R.styleable.html#AndroidManifestReceiver">&lt;receiver&gt;</a></code> tag)
restrict who can send broadcasts to the associated receiver.
The permission is checked <em>after</em>
<code><a href="../../../reference/android/content/Context.html#sendBroadcast(android.content.Intent)">Context.sendBroadcast()</a></code> returns,
as the system tries
to deliver the submitted broadcast to the given receiver.  As a result, a
permission failure will not result in an exception being thrown back to the
caller; it will just not deliver the intent.  In the same way, a permission
can be supplied to
<code><a href="../../../reference/android/content/Context.html#registerReceiver(android.content.BroadcastReceiver, android.content.IntentFilter, java.lang.String, android.os.Handler)">Context.registerReceiver()</a></code>
to control who can broadcast to a programmatically registered receiver.
Going the other way, a permission can be supplied when calling
<code><a href="../../../reference/android/content/Context.html#sendBroadcast(android.content.Intent, java.lang.String)">Context.sendBroadcast()</a></code>
to restrict which BroadcastReceiver objects are allowed to receive the broadcast (see
below).</p>

<p><strong><code><a href="../../../reference/android/content/ContentProvider.html">ContentProvider</a></code></strong> permissions
(applied to the
<code><a href="../../../reference/android/R.styleable.html#AndroidManifestProvider">&lt;provider&gt;</a></code> tag)
restrict who can access the data in
a <code><a href="../../../reference/android/content/ContentProvider.html">ContentProvider</a></code>.  (Content providers have an important
additional security facility available to them called
<a href="#uri">URI permissions</a> which is described later.)
Unlike the other components,
there are two separate permission attributes you can set:
<code><a href="../../../reference/android/R.attr.html#readPermission">android:readPermission</a></code> restricts who
can read from the provider, and
<code><a href="../../../reference/android/R.attr.html#writePermission">android:writePermission</a></code> restricts
who can write to it.  Note that if a provider is protected with both a read
and write permission, holding only the write permission does not mean
you can read from a provider.  The permissions are checked when you first
retrieve a provider (if you don't have either permission, a SecurityException
will be thrown), and as you perform operations on the provider.  Using
<code><a href="../../../reference/android/content/ContentResolver.html#query(android.net.Uri, java.lang.String[], java.lang.String, java.lang.String[], java.lang.String)">ContentResolver.query()</a></code> requires
holding the read permission; using
<code><a href="../../../reference/android/content/ContentResolver.html#insert(android.net.Uri, android.content.ContentValues)">ContentResolver.insert()</a></code>,
<code><a href="../../../reference/android/content/ContentResolver.html#update(android.net.Uri, android.content.ContentValues, java.lang.String, java.lang.String[])">ContentResolver.update()</a></code>,
<code><a href="../../../reference/android/content/ContentResolver.html#delete(android.net.Uri, java.lang.String, java.lang.String[])">ContentResolver.delete()</a></code>
requires the write permission.
In all of these cases, not holding the required permission results in a
<code><a href="../../../reference/java/lang/SecurityException.html">SecurityException</a></code> being thrown from the call.</p>


<a name="broadcasts"></a>
<h3>Enforcing Permissions when Sending Broadcasts</h3>

<p>In addition to the permission enforcing who can send Intents to a
registered <code><a href="../../../reference/android/content/BroadcastReceiver.html">BroadcastReceiver</a></code> (as described above), you
can also specify a required permission when sending a broadcast. By calling <code><a href="../../../reference/android/content/Context.html#sendBroadcast(android.content.Intent, java.lang.String)">Context.sendBroadcast()</a></code> with a
permission string, you require that a receiver's application must hold that
permission in order to receive your broadcast.</p>

<p>Note that both a receiver and a broadcaster can require a permission. When
this happens, both permission checks must pass for the Intent to be delivered
to the associated target.</p>


<a name="enforcement"></a>
<h3>Other Permission Enforcement</h3>

<p>Arbitrarily fine-grained permissions can be enforced at any call into a
service. This is accomplished with the <code><a href="../../../reference/android/content/Context.html#checkCallingPermission(java.lang.String)">Context.checkCallingPermission()</a></code>
method. Call with a desired
permission string and it will return an integer indicating whether that
permission has been granted to the current calling process. Note that this can
only be used when you are executing a call coming in from another process,
usually through an IDL interface published from a service or in some other way
given to another process.</p>

<p>There are a number of other useful ways to check permissions. If you have
the pid of another process, you can use the Context method <code><a href="../../../reference/android/content/Context.html#checkPermission(java.lang.String, int, int)">Context.checkPermission(String, int, int)</a></code>
to check a permission against that pid. If you have the package name of another
application, you can use the direct PackageManager method <code><a href="../../../reference/android/content/pm/PackageManager.html#checkPermission(java.lang.String, java.lang.String)">PackageManager.checkPermission(String, String)</a></code>
to find out whether that particular package has been granted a specific permission.</p>


<a name="uri"></a>
<h2>URI Permissions</h2>

<p>The standard permission system described so far is often not sufficient
when used with content providers.  A content provider may want to
protect itself with read and write permissions, while its direct clients
also need to hand specific URIs to other applications for them to operate on.
A typical example is attachments in a mail application.  Access to the mail
should be protected by permissions, since this is sensitive user data.  However,
if a URI to an image attachment is given to an image viewer, that image viewer
will not have permission to open the attachment since it has no reason to hold
a permission to access all e-mail.</p>

<p>The solution to this problem is per-URI permissions: when starting an
activity or returning a result to an activity, the caller can set
<code><a href="../../../reference/android/content/Intent.html#FLAG_GRANT_READ_URI_PERMISSION">Intent.FLAG_GRANT_READ_URI_PERMISSION</a></code> and/or
<code><a href="../../../reference/android/content/Intent.html#FLAG_GRANT_WRITE_URI_PERMISSION">Intent.FLAG_GRANT_WRITE_URI_PERMISSION</a></code>.  This grants the receiving activity
permission access the specific data URI in the Intent, regardless of whether
it has any permission to access data in the content provider corresponding
to the Intent.</p>

<p>This mechanism allows a common capability-style model where user interaction
(opening an attachment, selecting a contact from a list, etc) drives ad-hoc
granting of fine-grained permission.  This can be a key facility for reducing
the permissions needed by applications to only those directly related to their
behavior.</p>

<p>The granting of fine-grained URI permissions does, however, require some
cooperation with the content provider holding those URIs.  It is strongly
recommended that content providers implement this facility, and declare that
they support it through the
<code><a href="../../../reference/android/R.styleable.html#AndroidManifestProvider_grantUriPermissions">android:grantUriPermissions</a></code> attribute or
<code><a href="../../../reference/android/R.styleable.html#AndroidManifestGrantUriPermission">&lt;grant-uri-permissions&gt;</a></code> tag.</p>

<p>More information can be found in the
<code><a href="../../../reference/android/content/Context.html#grantUriPermission(java.lang.String, android.net.Uri, int)">Context.grantUriPermission()</a></code>,
<code><a href="../../../reference/android/content/Context.html#revokeUriPermission(android.net.Uri, int)">Context.revokeUriPermission()</a></code>, and
<code><a href="../../../reference/android/content/Context.html#checkUriPermission(android.net.Uri, int, int, int)">Context.checkUriPermission()</a></code>
methods.</p>


    </div>

  <a href="#top" style="float:right">&uarr; Go to top</a>
  
  </div>

<div id="footer">


  <div id="copyright">
    
  Except as noted, this content is licensed under <a
  href="http://www.apache.org/licenses/LICENSE-2.0">Apache 2.0</a>. 
  For details and restrictions, see the <a href="../../../license.html">
  Content License</a>.
  </div>
  <div id="build_info">
    
  Android 4.0&nbsp;r1 - 17 Oct 2011 18:17

  </div>

  <div id="footerlinks">
    
  <p>
    <a href="http://www.android.com/terms.html">Site Terms of Service</a> -
    <a href="http://www.android.com/privacy.html">Privacy Policy</a> -
    <a href="http://www.android.com/branding.html">Brand Guidelines</a>
  </p>
  </div>

</div> <!-- end footer -->

</div><!-- end doc-content -->

</div> <!-- end body-content --> 

<script type="text/javascript">
init(); /* initialize android-developer-docs.js */
var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
</script>
<script type="text/javascript">
var pageTracker = _gat._getTracker("UA-5831155-1");
pageTracker._trackPageview();
</script>

</body>
</html>



